I need to get this program to store the values for a persons firstname and surname in a database. The database is called Class and the table inside it that I am trying to insert data into is called Names.
I have tried to rearrange this several times and removed it from its try loop to try diagnose the issue. Thanks in advance. I will help the best I can :)
new_first,new_surname = str(input("Firstname:\t")), str(input("Surname:\t"))
new_name = [new_surname, new_first]
print(new_name)
c.executemany("INSERT INTO Names VALUES (?,?)", new_name)
The error message I keep getting is:
Incorrect number of bindings supplied. The current statement uses 2, and there are 7 supplied.
Don't use cursor.executemany(), use cursor.execute():
c.execute("INSERT INTO Names VALUES (?,?)", new_name)
executemany() should be used for multiple rows of data, but you have just one.
The error is caused by the executemany() method treating new_surname as a row by itself, and since a string is iterable an attempt is made to use every individual character from that string as a parameter. A string length of 7 would give you 7 parameters, and that doesn't match the 2 in the SQL statement.
If you do have many rows, then each row would have to consist of a last and first name value for the two parameters:
new_names = [
[new_surname, new_first],
['another surname', 'another first name'],
# ...
]
c.executemany("INSERT INTO Names VALUES (?,?)", new_names)
executemany() expects many items, as the name suggests.
That means a list of lists, or any similar data structure. You give it only one item.
new_first, new_surname = str(input("Firstname:\t")), str(input("Surname:\t"))
new_name = [[new_surname, new_first]]
c.executemany("INSERT INTO Names VALUES (?,?)", new_name)
or use execute if you only have one item
new_first, new_surname = str(input("Firstname:\t")), str(input("Surname:\t"))
new_name = [new_surname, new_first]
c.execute("INSERT INTO Names VALUES (?,?)", new_name)
Related
I'm trying to populate a database with a single column with a list of strings (links). I scraped the list and I must modify every single link before sending it to the database. This is the code:
for event in events:
link_url = "https://www.website.com"+event+"#all"
c.execute("INSERT INTO table (links) VALUES(?)", link_url)
I can get it working if I modify the variables and send a tuple, like this:
for event in events:
link_url = "https://www.website.com"+event+"#all"
link = (link_url,)
c.execute("INSERT INTO seriea (links) VALUES(?)", link_url)
but I don't want to use this solution since I want to get a list of strings back out later:
c = connection.execute('select links from table')
list_of_urls = c.fetchall()
But this gives me a list of tuples.
This is the error I have: ProgrammingError: Incorrect number of bindings supplied. The current statement uses 1, and there are 80 supplied.
I think that's because the string characters are counted (actually more but I noticed that the number before "supplied" changes with the link fed)
I don't want to use this solution since I want to get a list of strings back out later:
c = connection.execute('select links from table')
list_of_urls = c.fetchall()
But this gives me a list of tuples.
The list of tuples you're getting when you do a select have nothing to do with the way you insert data. Remember, tables have two dimensions:
id
links
something
else
1
"foo"
"bar"
"baz"
2
"quux"
"herp"
"derp"
When you do a select you get a list that corresponds to the rows here. But each row has multiple fields: id, links, something, and else. Each tuple in the list contains the values for each of the fields in the table.
If you just want the URLs as a list of strings you can use a list comprehension or similar:
c = connection.execute('select links from table')
list_of_rows = c.fetchall()
list_of_strings = [row[0] for row in list_of_rows]
# ^ index of first element in
# ^^^ the tuple of values for each row
Note that you do have to provide a tuple or other sequence when you insert the data:
For the qmark style, parameters must be a sequence. For the named style, it can be either a sequence or dict instance. The length of the sequence must match the number of placeholders, or a ProgrammingError is raised. If a dict is given, it must contain keys for all named parameters.
You might be thinking of the tuple part of it the wrong way. You don't need to pass in a tuple of URLs, you need to pass in a tuple of parameters. You're not saying "the links column should contain this tuple" but rather "this tuple contains enough values to fill in the placeholders in this query".
I'd rewrite that like so:
for event in events:
link_url = "https://www.website.com"+event+"#all"
c.execute("INSERT INTO seriea (links) VALUES(?)", (link_url,))
This is so you can have multiple parameters, e.g.
c.execute(
"INSERT INTO seriea (links, some, other) VALUES(?, ?, ?)",
(link_url, foo, bar),
)
The current statement uses 1, and there are 80 supplied.
I think that's because the string characters are counted
Yes, that's most likely what's happening. c.execute() expects to receive a sequence, and strings are a sequence of characters.
lst = [{'Fruit':'Apple','HadToday':2},{'Fruit':'Banana','HadToday':8}]
I have a long list of dictionaries of the form above.
I have two fixed variables.
person = 'Sam'
date = datetime.datetime.now()
I wish to insert this information into a mysql table.
How I do it currently
for item in lst:
item['Person'] = person
item['Date'] = date
cursor.executemany("""
INSERT INTO myTable (Person,Date,Fruit,HadToday)
VALUES (%(Person)s, %(Date)s, %(Fruit)s, %(HadToday)s)""", lst)
conn.commit()
Is their a way to do it, that bypasses the loop as the person and date variables are constant. I have tried
lst = [{'Fruit':'Apple','HadToday':2},{'Fruit':'Banana','HadToday':8}]
cursor.executemany("""
INSERT INTO myTable (Person,Date,Fruit,HadToday)
VALUES (%s, %s, %(Fruit)s, %(HadToday)s)""", (person,date,lst))
conn.commit()
TypeError: not enough arguments for format string
Your problem here is, that it tries to apply all of lst into %(Fruit)s and nothing is left for %(HadToday)s).
You should not fix it by hardcoding the fixed values into the statement as you get into troubles if you have a name like "Tim O'Molligan" - its better to let the db handle the correct formatting.
Not mysql, but you get the gist: http://initd.org/psycopg/docs/usage.html#the-problem-with-the-query-parameters - learned this myself just a week ago ;o)
The probably cleanest way would be to use
cursor.execute("SET #myname = %s", (person,))
cursor.execute("SET #mydate = %s", (datetime.datetime.now(),))
and use
cursor.executemany("""
INSERT INTO myTable (Person,Date,Fruit,HadToday)
VALUES (#myname, #mydate, %(Fruit)s, %(HadToday)s)""", lst)
I am not 100% about the syntax, but I hope you get the idea. Comment/edit the answer if I have a misspell in it.
I know this is a popular topic but I searched the various answers and didn't see a clear answer to my issue. I have a function that I want to use to insert records into my NDBC database that is giving me the error I mentioned in the title. The function is below:
def insertStdMet(station,cursor,data):
# This function takes in a station id, database cursor and an array of data. At present
# it assumes the data is a pandas dataframe with the datetime value as the index
# It may eventually be modified to be more flexible. With the parameters
# passed in, it goes row by row and builds an INSERT INTO SQL statement
# that assumes each row in the data array represents a new record to be
# added.
fields=list(data.columns) # if our table has been constructed properly, these column names should map to the fields in the data table
# Building the SQL string
strSQL1='REPLACE INTO std_met (station_id,date_time,'
strSQL2='VALUES ('
for f in fields:
strSQL1+=f+','
strSQL2+='%s,'
# trimming the last comma
strSQL1=strSQL1[:-1]
strSQL2=strSQL2[:-1]
strSQL1+=") " + strSQL2 + ")"
# Okay, now we have our SQL string. Now we need to build the list of tuples
# that will be passed along with it to the .executemany() function.
tuplist=[]
for i in range(len(data)):
r=data.iloc[i][:]
datatup=(station,r.name)
for f in r:
datatup+=(f,)
tuplist.append(datatup)
cursor.executemany(strSQL1,tuplist)
When we get to the cursor.executemany() call, strSQL looks like this:
REPLACE INTO std_met (station_id,date_time,WDIR,WSPD,GST,WVHT,DPD,APD,MWD,PRES,ATMP,WTMP,DEWP,VIS) VALUES (%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s)'
I'm using % signs throughout and I am passing a list of tuples (~2315 tuples). Every value being passed is either a string,datetime, or number. I still have not found the issue. Any insights anyone cares to pass along would be sincerely appreciated.
Thanks!
You haven't given your SQL query a value for either station_id or date_time, so when it goes to unpack your arguments, there are two missing.
I suspect you want the final call to be something like:
REPLACE INTO std_met
(station_id,date_time,WDIR,WSPD,GST,WVHT,DPD,APD,MWD,
PRES,ATMP,WTMP,DEWP,VIS) VALUES (%s, %s, %s,%s,%s,%s,
%s,%s,%s,%s,%s,%s,%s,%s)'
Note the extra two %s. It looks like your tuple already contains values for station_id and date_time, so you could try this change:
strSQL1='REPLACE INTO std_met (station_id,date_time,'
strSQL2='VALUES (%s, %s, '
I am trying to increment the count of a row in an SQLite database if the row exists, or add a new row if it doesn't exist the way it is done in this SO post. However I'm getting some weird behavior when I try to execute this SQL proc many times in quick succession. As an example I tried running this code:
db = connect_to_db()
c = db.cursor()
for i in range(10):
c.execute("INSERT OR REPLACE INTO subject_words (subject, word, count) VALUES ('subject', 'word', COALESCE((SELECT count + 1 FROM subject_words WHERE subject = 'subject' AND word = 'word'), 1));")
db.commit()
db.close()
And it inserted the following into the database
sqlite> select * from subject_words;
subject|word|1
subject|word|2
subject|word|2
subject|word|2
subject|word|2
subject|word|2
subject|word|2
subject|word|2
subject|word|2
subject|word|2
Which totals to 19 entries of the word 'word' with subject 'subject'. Can anyone explain this weird behavior?
I don't think you've understood what INSERT OR REPLACE actually does. The REPLACE clause would only come into play if it was not possible to do the insertion, because a unique constraint was violated. An example might be if your subject column was the primary key.
However, without any primary keys or other constraints, there's nothing being violated by inserting multiple rows with the same subject; so there's no reason to invoke the REPLACE clause.
That operation is much easier to write and understand if you do it with two SQL statements:
c.execute("""UPDATE subject_words SET count = count + 1
WHERE subject = ? AND WORD = ?""",
['subject', 'word'])
if c.rowcount == 0:
c.execute("INSERT INTO subject_words (subject, word, count) VALUES (?,?,?)",
['subject', 'word', 1])
This does not require a UNIQUE constraint on the columns you want to check, and is not any less efficient.
I'm trying to check whether a record already exists in the database (by similar title), and insert it if not. I've tried it two ways and neither quite works.
More elegant way (?) using IF NOT EXISTS
if mode=="update":
#check if book is already present in the system
cursor.execute('IF NOT EXISTS (SELECT * FROM book WHERE TITLE LIKE "%s") INSERT INTO book (title,author,isbn) VALUES ("%s","%s","%s") END IF;' % (title,title,author,isbn))
cursor.execute('SELECT bookID FROM book WHERE TITLE LIKE "%s";' % (title))
bookID = cursor.fetchall()
print('found the bookid %s' % (bookID))
#cursor.execute('INSERT INTO choice (uid,catID,priority,bookID) VALUES ("%d","%s","%s","%s");' % ('1',cat,priority,bookID)) #commented out because above doesn't work
With this, I get an error on the IF NOT EXISTS query saying that "author" isn't defined (although it is).
Less elegant way using count of matching records
if mode=="update":
#check if book is already present in the system
cursor.execute('SELECT COUNT(*) FROM book WHERE title LIKE "%s";' % (title))
anyresults = cursor.fetchall()
print('anyresults looks like %s' % (anyresults))
if anyresults[0] == 0: # if we didn't find a bookID
print("I'm in the loop for adding a book")
cursor.execute('INSERT INTO book (title,author,isbn) VALUES ("%s","%s","%s");' % (title,author,isbn))
cursor.execute('SELECT bookID FROM book WHERE TITLE LIKE "%s";' % (title))
bookID = cursor.fetchall()
print('found the bookid %s' % (bookID))
#cursor.execute('INSERT INTO choice (uid,catID,priority,bookID) VALUES ("%d","%s","%s","%s");' % ('1',cat,priority,bookID)) #commented out because above doesn't work
In this version, anyresults is a tuple that looks like (0L,) but I can't find a way of matching it that gets me into that "loop for adding a book." if anyresults[0] == 0, 0L, '0', '0L' -- none of these seem to get me into the loop.
I think I may not be using IF NOT EXISTS correctly--examples I've found are for separate procedures, which aren't really in the scope of this small project.
ADDITION:
I think unutbu's code will work great, but I'll still getting this dumb NameError saying author is undefined which prevents the INSERT from being tried, even when I am definitely passing it in.
if form.has_key("title"):
title = form['title'].value
mode = "update"
if form.has_key("author"):
author = form['author'].value
mode = "update"
print("I'm in here")
if form.has_key("isbn"):
isbn = form['isbn'].value
mode = "update"
It never prints that "I'm in here" test statement. What would stop it getting in there? It seems so obvious--I keep checking my indentation, and I'm testing it on the command line and definitely specifying all three parameters.
If you set up a UNIQUE index on book, then inserting unique rows is easy.
For example,
mysql> ALTER IGNORE TABLE book ADD UNIQUE INDEX book_index (title,author);
WARNING: if there are rows with non-unique (title,author) pairs, all but one such row will be dropped.
If you want just the author field to be unique, then just change (title,author) to (author).
Depending on how big the table, this may take a while...
Now, to insert a unique record,
sql='INSERT IGNORE INTO book (title,author,isbn) VALUES (%s, %s, %s)'
cursor.execute(sql,[title,author,isbn])
If (title,author) are unique, the triplet (title,author,isbn) is inserted into the book table.
If (title,author) are not unique, then the INSERT command is ignored.
Note, the second argument to cursor.execute. Passing arguments this way helps prevent SQL injection.
This doesn't answer your question since it's for Postgresql rather than MySQL, but I figured I'd drop it in for people searching their way here.
In Postgres, you can batch insert items if they don't exist:
CREATE TABLE book (title TEXT, author TEXT, isbn TEXT);
# Create a row of test data:
INSERT INTO book (title,author,isbn) VALUES ('a', 'b', 'c');
# Do the real batch insert:
INSERT INTO book
SELECT add.* FROM (VALUES
('a', 'b', 'c'),
('d', 'e', 'f'),
('g', 'h', 'i'),
) AS add (title, author, isbn)
LEFT JOIN book ON (book.title = add.title)
WHERE book.title IS NULL;
This is pretty simple. It selects the new rows as if they're a table, then left joins them against the existing data. The rows that don't already exist will join against a NULL row; we then filter out the ones that already exist (where book.title isn't NULL). This is extremely fast: it takes only a single database transaction to do a large batch of inserts, and lets the database backend do a bulk join, which it's very good at.
By the way, you really need to stop formatting your SQL queries directly (unless you really have to and really know what you're doing, which you don't here). Use query substitution, eg. cur.execute("SELECT * FROM table WHERE title=? and isbn=?", (title, isbn)).